Mayor Bill de Blasio pledged yesterday to make New York the first city in the nation to require private employers to provide at least two weeks of paid vacation to all employees. If passed, the proposal would cover about 500,000 workers who currently go without paid time off. The proposal, which requires City Council approval, comes a day after Mr. de Blasio announced a $100 million effort to help ensure that the city’s health care resources are used by the uninsured, including undocumented immigrants — a move that immediately set up a contrast with Republican leadership in Washington.

Mr. de Blasio appeared eager to billboard that contrast with both announcements, leading to speculation among political consultants in New York City that his larger aim leading up to his State of the City address on Thursday is to thrust his name back into the national conversation as a leader of progressive Democratic principles.

Mr. de Blasio did nothing to alter that impression during a news conference in City Hall, in which he presented his plan for paid time off as a link in the long history of workers’ rights initiatives going back to the New Deal. He said that he would travel the country “very soon” to encourage other cities and states to follow suit.

“I’m focused on New York City, but I know what we do here could have a huge impact on the rest of the country,” Mr. de Blasio said. “I’m going to go out and talk about the things we’re doing here and the impact that they can make. I’m going to push other leaders to take on these ideas. I’m certainly going to push my party to support these kind of ideas.”

From almost the moment he became mayor, Mr. de Blasio has looked to extend his political reach beyond New York City, though his efforts have not always succeeded.

Now in the second year of his second term, the mayor seems to be renewing those efforts in earnest. He revealed the health care plan in a national television interview on MSNBC; he announced the paid vacation plan, which city officials say could benefit about half a million workers, in The Washington Post.

But while the promise on health care largely amounted to improving customer service for coverage that has existed for decades, the paid-vacation measure would be genuinely new. No state or city in the United States has such a requirement, according to City Hall, though Puerto Rico does guarantee paid time off.

The mayor presented a list of mostly European countries that he said require paid time off for workers.